Parasitic diseases continue to be an important cause of morbidity and mortality worldwide. The last decade has provided a series of new tools for parasite control, however these are not yet thoroughly applied in developing countries where most emerging and re-emerging parasitic infectious occur. This program aims to strengthen and interrelate four already existing research lines in Peru, that will be used as a comprehensive framework for the concerted use of these new tools. A core structure covering molecular biology, immunology, and epidemiology will enhance the shared use of new technology for the diagnosis, treatment, and control of endemic parasitic diseases. Rapid sero-reversion, a phenomenon that changes the understanding of the transmission dynamics of Taenia solium cysticercosis, will be evaluated to dissect its biological significance In order to improve E. granulosus control methods, fast-track alternatives will be sought by defining transmission dynamics, targeting the definitive host. The basic patterns methods, fast-track alternatives will be sought by defining transmission in endemic zones of Cyclospora cayetanensis, will be described patterns of transmission in endemic zones of Cyclospora cayetanensis, will be described and detailed using new serological and DNA techniques. Molecular mechanisms of resistance in American leishmaniasis will be studied and characterized.